1. Field of the Invention
The present invention relates to a shielded electrical connector, and particularly to an SCA-2 connector having a rear shield that can be easily attached to and detached from an insulative housing of the connector when desired.
2. Description of Prior Art
SCA-2 (Single Connector Attachment) connectors provide a standard interface between SCSI (Small Computer System Interface) disk drives, Fiber Channel disk drives, GBIC (Gigabit Interface Converter) modules and back-plane systems. The SCA-2 connectors conform to the SFF standard established by the Small Form Factor Committee, and can be classified into 3 types, i.e., 20-pin, 40-pin and 80-pin SCA-2 connectors. The 20-pin SCA-2 connectors are used with GBIC modules used as media interface modules for fiber channel; the 40-pin SCA-2 connectors are used with 3.5xe2x80x3 Fiber Channel disk drives; and the 80-pin SCA-2 connectors are used with 3.5xe2x80x3 SCSI disk drives.
With the ever-increasing requirement for high-speed signal transmission, shielding and grounding capabilities are becoming increasingly important for electrical connectors. Such shielding and grounding means are generally used for protection against EMI (Electromagnetic Interference) and ESD (Electrostatic Discharge). To assemble a shield to an insulative housing of the electrical connector, additional fastening devices, such as screws, nuts and pegs, are normally used, whereby the assembly and disassembly process of the shield is troublesome and manufacturing cost is also increased.
Additionally, one problem with a conventional SCA-2 connector is that contacts received in an insulative housing thereof are not completely shielded from EMI, since only front contact portions of the contacts are shielded, while rear tail portions are exposed.
Therefore, an additional rear shield for an SCA-2 connector which can be easily attached to and detach from the connector is required for overcoming the above disadvantages of the prior art.
Accordingly, one object of the present invention is to provide an SCA-2 connector having a rear shield to promote EMI-free signal transmissions in cooperation with an existing front shield.
Another object of the present invention is to provide an SCA-2 connector having a rear shield which can be easily attached to and detached from an insulative housing without additional fastening devices, thereby facilitating convenient assembly and disassembly of the rear shield and reducing manufacturing costs.
A further object of the present invention is to provide an SCA-2 connector having grounding mechanisms for establishing a grounding path between a complementary SCA-2 connector and a printed circuit board on which the SCA-2 connector is mounted.
In order to achieve the objects set forth, an SCA-2 connector in accordance with the present invention comprises an insulative housing, a plurality of contacts received in the housing, a pair of board locks retained in the housing, and a shield consisting of a front shield and a rear shield cooperatively enclosing the housing.
According to one aspect of the present invention, the front shield encloses front contact portions of the contacts, and the rear shield encloses rear right-angle bent tail portions of the contacts, whereby improved EMI shielding capabilities are provided.
According to a second aspect of the present invention, the housing comprises a plurality of recesses and a pair of partitions each with a ledge formed on an outer side surface thereof. The rear shield has forwardly projecting retaining tabs for being inserted into corresponding recesses of the housing to prevent rearward movement of the rear shield relative to the housing, and a forwardly exposed slot defined in each side wall thereof for fittingly receiving a corresponding ledge of the housing to prevent vertical and forward movements of the rear shield relative to the housing. Thus, the rear shield is retentively assembled to the housing, and assembly and disassembly of the rear shield are also facilitated since no additional fastening devices are required.
According to a third aspect of the present invention, each board lock comprises a front engaging portion for mating with a corresponding ground contact of a complementary SCA-2 connector, and a rear insertion portion for being inserted into a printed circuit board. The rear shield has a pair of pins downwardly extending from a partition thereof for being connected with grounding circuits of the printed circuit board, and a spring tang stamped from each side wall thereof for biasing against a side surface of the rear insertion portion of the board lock. A grounding path is thus established between the complementary SCA-2 connector and the printed circuit board via the board locks, the spring tangs and the pins of the SCA-2 connector.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.